SOLUTION: Two bicyclists are 180 miles apart when they start racing towards each other. If their speeds are 14 mph and 16 mph respectively, how long will it be before they are twenty miles a

Algebra ->  Finance -> SOLUTION: Two bicyclists are 180 miles apart when they start racing towards each other. If their speeds are 14 mph and 16 mph respectively, how long will it be before they are twenty miles a      Log On


   

Question 1100462: Two bicyclists are 180 miles apart when they start racing towards each other. If their speeds are 14 mph and 16 mph respectively, how long will it be before they are twenty miles apart?
TYSM IF YOU HELP! PLEASE DO THIS ASAP THIS IS DUE TOMORROW >.<
Found 2 solutions by Alan3354, KMST:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Speeds are added when going in opposite directions.
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"respectively" serves no purpose.

Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
Racing towards each other, the distance between them will decrease at a rate of
14 mph + 16 mph = 30 mph.
We want the distance between them to change from the 180 miles at the start,
to 20 miles.
That is a difference of 180 miles - 20 miles = 160 miles
Decreasing the distance between then at a rate of 30 miles per hour,
it will take them 160%2F30hours=16%2F3hours=5%261%2F3hours=5+hoursand20minutes .

You could write it in equations as
t= time racing in hours until they are 20 miles apart
180-14t-16t=20
180-30t=20
180-20=30t
160=30t
160%2F30=t
t=16%2F3=5%261%2F3 and 1/3 of an hour is 60minutes%2F3=20minutes ,
so it will be 5 hours and 20 minutes until they are 20 miles apart.